Starting in 2009, a 30-something South Korean man with the last name Jo began traveling to northeastern China. There, he met North Koreans who were government agents.

Jo allegedly met with the agents to ask them to develop game software for a cyber attack on South Korea. Those games would turn players' computers against their own country.

The South Korean man, who worked as game distributor, shelled out tens of millions of Korean won (several hundred thousand dollars) for the games, which were infected with malignant viruses. South Korean authorities state that Jo knew the men were North Korean agents and knew the games were malware, but still sold the games to South Korean online game operators.

According to Korea JoongAng Daily, when South Korean gamers played the games, the viruses embedded in them turned the computers into zombie computers that could be controlled for cyber attacks. Through these zombie computers, a distributed denial-of-service attack was launched against Incheon International Airport.

The attack was launched several times in March 2011.

Jo was arrested this weekend for violating the National Security Law.

This same North Korean government department, the Reconnaissance General Bureau, is also behind a cyber attack last fall that caused a technical glitch in the airport's flight data processor, affecting the departures of 18 flights.

Authorities don't know if last September's glitch is related to Jo's gaming malware.